NNMT and hepatocellular carcinoma: Accumulating evidence indicates that NNMT is highly expressed in numerous malignancies, including renal cell cancer 8, breast cancer 9, 10, non-small cell lung cancer 11, 12, bladder cancer 13, cervical cancer 14, gastric cancer 15, 16, ovarian cancer 17, 18, esophageal squamous cell carcinoma 19, hepatocellular carcinoma 20, 21 and endometrial cancer 22.